Retort furnace



F. A. HANSEN Get. 6, 1931.

RETORT FURNACE Filed Aug. 10, 1929 3 Sheets-Sheet' l luunnmuun F. A.HANSEN 1,825,790

RETORT FURNAC E Oct. 6, 1931.

3 Sheets-Sheet 2 Filed Aug. 10

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ATTORNEY F. A. HANSEN RETORT FURNACE Oct. 6, 1931.

Filed Aug. 10, 1929 3 Sheets-Sheet 3 m NW N N N W mm T Patented Oct. 6,1931 UNITED STATES PATENT OFFICE FRED' A. HANSEN, OF MILWAUKEE,WISCONSIN, ASSIGNOR TO HEVI DUTY ELECTRIC COMPANY, OF MILWAUKEE,WISCONSIN, A CORPORATION OF WISCONSIN i BETORT FURNACE Application filedAugust 10, 1929. Serial No. 384,952.

My invention relates broadly to retort furnaces and more particularlyto-a retort furnace of the liquid-seal type.

One of the objects of my invention is to provide a retort furnace havingmeans for circulating air or gases within the'furnace for securinguniform temperature throughout the charge, the circulating air or gasesbeing confined within the retort.

Another object of my invention is'to provide a construction of retortfurnace of the liquid-seal type in which the speed of production may beincreased at the same time that a more, uniform temperature may bemaintained throughout the charge in the furnace.

Still another object of my invention is to .provide a construction ofretort furnace of the water-seal type having means for removablycarrying the charge within the retort furnace, with means forcirculatlng a1r or gases within the furnace for heating the bottomportion of the charge as rapldly as that portion of the charge which islocated remote from the water-seal.

A further object of my invention is to provide a-construction of retortfurnace in which the temperature gradient existing between the furnacechamber and the interior of the retort may be reduced for avoiding thetendency of collapse of the walls of the retort due to the externalsurface being at a higher temperature than the internal surface of there-' tort.

A still further object of my invention is to provide a construction ofretort furnace of the water-seal type, wherein there 1s a substantialreduction of the time cycle necessary to thoroughly saturate a chargeand maintain such charge ata uniform temperature over a predeterminedtime interval.

A further object of my invention is to provide a construction ofwater-seal retort furnace wherein an elevator structure is employed toraise and lower a charge preparatory for heat treatment wlthin theretort furnace, the elevator structure havlng a multlplicity ofhorizontally disposed baflle plates thereon for controlling the path ofair or gases through the interior of the retort furnace and confiningthe heat within the retort furnace.

Other and further objectsof my invention reside in the construction ofretort furnace described in the specificationhereinafter following byreference to the accompanying drawings in which:

Fig. 1 is a cross-sectional view through the retort furnace of myinvention with some of the parts shown in side elevation; Fig. 2 is alateral cross-sectional view through the retort furnace on line 22 ofFig. 1; Fig.

3 is an enlarged cross-sectional view showing the arrangement of baflieplates and perforated platform on the elevator and cooperating deflectorplate in the retort by which the directed circulation of air or gases isconfined within the retort; Fig. 4 is a cross-sectional view showing amodified arrangement of retort furnace embodying the principles of myinvention; Fig. 5 is a lateral cross-sectional view taken through theretort furnace of Fig. 4 on line 5-5 thereof; Fig. 6 is a fragmentarycross-sectional view on line 6-6 of Fig. 7 showing the arrangement of amodified structure of retort employing my invention; Fig. 7 is avertical cross-sectional view taken on line 77 of Fig. 6 and showing therelative arrangement of walls of the retort illustrated in thecross-sectional View of Fig. 6; Fig. 8 is a longitudinal cross-sectionalview taken through a further modified form of retort furnace embodyingthe principles of my invention; Fig. 9 is a plan view partially incross-section showing the arrangement of parts in the modified retortfurnace structure of Fig. 8; Fig. 10 is a lateral cross-sectional viewshowing a modified arrangement of the walls of a retort constructedaccording to the general plan of the retort in Figs. 8 and 9; Fig. 11 isa longitudinal cross-sectional view taken on line 11-1l of the modifiedarrangement of retort walls shown in Fig. 10; and Figs. 12 and 13 areviews of the bafiie plates 41 which are used for directing the air fromthe fans to the lines in the construction of retort furnace shown inFigs. 8 and 9.

Referring to the drawings in more detail the retort furnace of myinvention is illustrated as including a furnace chamber 1 which 100 maybe heated by any suitable means such as gas or by means of electricalresistors mounted in any suitable manner familiar to those versed in theart, or as, for example by the method disclosed in copending applicationSerial No. 279,810, filed May 27, 1928, by Edwin L. Smalley for heatingelement mounting construction. The furnace is enclosed by a shell 3which surrounds the fur.- nace walls which may be of the customary formof inner fire-brick lining such as represented at 2 surrounded bysuitable insulating materials 4. The furnace retort proper is shown at 5in the form of a corrugated wall having a generally cylindrical contourter minatlng in a conical top portion at 511 to which is secured thethroat or stack indicated by reference character 6. The inner lining ofthe retort is shown at 7 comprising a substantially cylindricalenclosure which fits within the corrugated wall 5. The inner lining 7terminates in an annular inturned flange portion 8 freely suspendedinside of the retort 5 by means of straps-represented at 32. The retort5 and lining 7 may be of any suitable material such as sheet or castnon-oxidizing metal. The annular top plate 8 of lining 7 is apertured at9 in the form of a circular opening for the passage of air and gaseswithin the retort, as will be more fully described hereinafter.

The elevator which conveys and supports the load which is subjected toheat treatment is comprised in part by a plunger or piston 10 formingpart of any suitable type of cylinder hoist not shown. On the top ofsuch piston is mounted a suitable load platform 11. The load platform 11is preferably perforated as represented at 110, and carries the loadwhich is designated in dotted lines at 11b. The load which is treatedmay be of a variety of different forms, such as a charge consistingusually of copper in coils or in the form of rods, wires or tubes. Theload platform 11 has suspended therefrom a multiplicity of deflector orbafile plates 23, 24, 25, and 26 which are supported with respect to theload platform by any suitable means such as rod rivets 30 and spacers 31which may be short lengths of tubing surrounding portions of the rodrivets 30. The bottom deflector plate 26 is located closely adjacent thelevel of the water seal shown at 27, and the other plates are separatedin spaced relation, the widest spacing occurring between baffle plate 23and platform 11.

Adjacent the bottom of the retort lining 7 I provide an annular plate 29which is sus' pended by means of straps or supports 33 attached to therespective parts by any suitable method such as by welding. The annularplate 29 is preferably formed. with an upturned inner edge shown at 29cwhich cooperates with flues 20 formed between lining 7 and retort 5, aswill be hereinafter explained.

On top of stack 6 is located a fitting having a flapper valve 12 whichmay be opened an outer collar 17 attached to stack 6 by any suitablemeans such as riveting or welding. The bearing 15 is connected to theouter collar 17 by webs 16, thus leaving apertures through whichexcessive steam may escape through valve 12 as heretofore outlined.Shaft 14 has a suitable top hearing such as a radial thrust ball bearing18, above which is mounted on the same shaft any suitable driving meansshown as a V grooved sheave 19. In place of sheave 19 a sprocket may beused receiving a driving chain from any source of power, such as anelectric motor, not shown.

Revolution of centrifugal fan 13 creates an air circulation resulting inthe upward suction of air indicated by arrows 21, and donuiward flowthrough flucs 20 with the di' rectional flow indicated by arrows 22. Thedischarge of heating air is deflected from flues 20 by the annular plate29 and also is further deflected slightly upward and away from thebaffle plates 23, 24, 25 and 26 by upturned edge 29a. The diameter, orsize, of baffle 24 with respect to the size of baflle 23 and withrespect to the size of the opening in the deflector plate 29 is such asto cause the greatest suction or siphoning of air between bafiie plates23 and 24 as indicated by arrows 22a and 28. The velocity of circulationfrom flues 20 is most effective in suction of air strata in such nearestor adj acent spaces; therefore to a less extent from the air stratumbetween deflector plates 24 and 25, as indicated by arrow 28a. Due tothe remote location of the air stratum below deflector plate 25 and theair stratum below deflector plate 26, there is practically no disturbance of the latter air strata by the discharge of heated air pastdeflector plate 29. There is, of course, a further tendency for the coolair adjacent to the water level to remain adjacent to the cooling eflectof the water.

The forced upward flow of heat. chilled by absorption of the heat intothe loadinside the retort helps in the equal distribution of heatextracted by the downward flow of air in the flues inside the retort. Bythis forced directional flow of air caused by the fan and flues, I canobtain the same quantity of heat inside the retort from a lowertemperature in the furnace chamber than exists in a retort without theforced circulation. In the present day practice, it has been the customto release from the bottom of the furnace chamber as much as 100% moreheat per square foot of heat releasing surface than in the upper zone ofthe furnace chamber. This has been necessary to attempt to drive theheat to the bottom of the charge. With this forced circulation and thedischarge of highly heated air to the bottom of the load, I overcomethese undesirable characteristics.

Furthermore, it will be readily recognized that with the forcedcirculation of the heat, with the discharge ports venting to theunderside of the charge, it will result in a quicker distribution ofheat with a simultaneous better uniformity of heat saturation, and atthe same time reduce the time cycle of effecting a complete uniformityof temperature.

While the corrugated form of retort shown at 5 is a preferred form as itgives additional heat absorbing and heat releasing surface while at thesame time it is affording an easy means of forming flues 20, I show inFigs. 4 and 5 a modified form of the retort wherein the lining 35 is ofthe corrugated type and the retort 34 is of the plain cylindrical typeforming flues 20 with other parts similar to those more fully describedin the foregoing.

In Figs. 6 and 7 I show still another form of a retort 36 of a plaincylindrical type having a plain cylindrical lining 37 forming a returnfine 20, with other parts similar to those heretofore described.

In Figs. 8 and 9 I show a modified form in which both the retort andlining 38 and 39 are of a modified fluted or corrugated type, formingflues 20. Thus it will be seen that the construction may be adapted alsoto an oval type retort, or any similar shape more suitable for thepurpose intended. In this rectangular form of Figs. 8 and 9 the topplate 8 has two annular openings 40, and two fans 13. In order to assistin the directional flow of air from the fan ports, I preferably usebaffle plates 41 so that the air discharged from either fan will notinterfere with the directional flow of air from the other fan.

I have shown in the several forms of the retort furnace the flues 20extending vertically. It is obvious that corrugations may be formed inthe retort or lining with the flutings running transversely orhorizontally instead of vertically as shown. In this case I form a flueby the proper relationship as to distance between the retdrt and thelining. In some cases I prefer the horizontal fluting in the retort forthe purpose of strengthening the side of the retort, as for instance inFigs. 8 and 9, where obviously horizontal flutings in the retort wouldstrengthen the 7 side of the -retort. Furthermore, with the horizontalflutings thus projecting inwardly toward the flues there is obtained apreferred stirring or swirling action to the air when passing downthrough the flue.

The modified form of retort wall having horizontal flutings has beenillustrated in Figs. 10 and 11 where the lining 44 is provided withvertically extending flutings shown at 45 while the retort 42 isprovided with horizontally extending flutings 43 spaced from theflutings 45 by a gap 46, thus permitting the circulation of gases or airtherebetween while obtaining increased strength in the retort walls.

In Figs. 12 and 13, I have shown views of the bafile plates 41 which Iemploy between the fans 13 in the structure of retort furnace shown inFigs. 8 and 9 for preventing interference in the circulating aircurrents.

While I have not shown the method of is then rolled into position andthe elevator V raises the load to its operative position as shown inFig. 1.

In some instances, I may prefer to construct the furnace without bafiieplates below the load platform but with flues formed by the retort andthe lining in one or more of the forms shown.

While I have described my invention in certain preferred embodiments, Idesire that it be understood that modifications may be made and that nolimitations upon my invention are intended other than are imposed by thescope of the appended claims.

i What I claim as new and desire to secure by Letters Patent of theUnited States is as follows:

1. A retort furnace comprising a housing,

a retort having an open bottom positioned within said housing, a liningfor said retort, flues formed by said retort and said lining, a liquidseal at the base of said retort, and an elevator supporting a load, saidelevator be-' ing movable through the open bottom of said retort andcarrying a multiplicity of bafile plates thereon adapted to be alignednormal to the aforementioned flues for directing the circulation of aircurrents within said retort.

2. In a retort furnace, a furnace housing,

a retort having an open bottom disposed in said housing, a liquid sealfor the base of said retort, a lining disposed within said retort andforming a multiplicity of flues with said retort for the circulation ofair currents through said retort, and a load elevator adapted to carrythe load under heat treatment, said load elevator being movable to aposition into and out of said retort, and a multiplicity of horizontallydisposed baflie plates carried by said elevator normal to theextremities of said fines for directing the circulation of air currentsto a position within said retort.

3. In a retort furnace, a furnace housing, a retort having an openbottom positioned within said housing, a lining for said retort, fluesformed by said lining and said retort, means for creating a forcedcirculation of air through said flues, said fines terminating short ofthe lower extremity of said retort, a load elevator movable to aposition within or out of said retort, said load elevator having amultiplicity of horizontally disposed battles thereon arranged toregister with the lower extremities of said fines for directing thecirculation of air within said retort when the load is moved to aposition for heat treatment within the retort.

4. In a retort furnace, a furnace housing, a retort having an openbottom disposed in said housing, a lining for said retort, amultiplicity of tlues formed by said retort and said lining, means forcreating a forced circula tion of air through said flues, an annularplate carried by said retort adjacent the end of said lines, a loadelevator movable to a po sition within or out of said retort, said loadelevator carrying a multiplicity of horizontally disposed bafiie platesthereon, said baflle plates being spacially related one with respect tothe other and being movable to a position above and below said annularplate for directing the circulation of air within said retort during theprocess of heat treatment of a load supported by said elevator.

5. In a retort furnace, a housing, a retort having an open bottomdisposed within said housing, a liquid seal for the base of said retort,a lining within said retort, flues formed by said lining and saidretort, means positioned within the head of. said retort for creating aforced circulation of air between said flues and through said retort, anannular plate member extending from the inner wall of said retort normalto the lower extremities of said flues and below to the lower extremityof said lining, a load elevator movable to a position through saidannular plate member for supporting a load within said retort, saidelevator having a multiplicity of horizontally extending bafiies thereonparallel to said annular plate member for substantially closing the baseof said retort.

6. In a retort furnace, a furnace housing, a retort having an openbottom mounted within said housing, a liquid seal for the base of saidretort, a lining within said retort, fiues formed by said lining andsaid retort, means for creating a forced circulation of air through saidflues and through said retort,

teamed an annular plate member carried by said retort in a planesubstantially normal to the extremities of said flues, said plate memberbeing positively spaced from the lower extermity of said lining andhaving an upwardly directed inner edge portion thereon, a load elevatorarranged to be moved to a position within said retort through saidannular plate member for supporting a load for heat treatment withinsaid retort, and a multiplicity of battles carried by said elevator,said baffles being movable to a position above and below the upwardlydirected inner edge portion on said plate member for directing thecirculation of air within said retort.

7. In a retort furnace, a furnace housing, a retort having an openbottom mounted within said housing, a liquid seal for the base of saidretort, a lining within said retort, flues formed by said lining andsaid retort, means for creating a forced circulation of air through saidfiues and through said retort, an annular plate member carried by saidretort in a plane substantially normal to the extremities of said fines,said plate member being positively spaced from the lower extermity ofsaid lining and having an upwardly directed inner edge portion thereon,a load elevator arranged to be moved to a position within said retortthrough said annular plate member, said elevator having a platformthereon and a multiplicity of battle plates disposed in horizontalplanes below said platform, said platform being apertured for thecirculation of air discharged by said flues under the guidance of theupwardly directed inner edge portion of said plate member, said bafiieplates operating to direct the circulatort in a plane substantiallvnormal to the extremities of said flues, said plate member beingpositively. spaced from the lower extremity of said lining and having anupwardly directed inner edge portion thereon, a load elevator arrangedto be moved to a position within said retort through the upwardlydirected inner edge portion of said plate member, said elevatorcomprising a platform for supporting a load under heat treatment, and amultiplicity of spaced bafile plates of successively increasingdiameters suspended below said platform, said platform being aperturedfor the assage of air currents discharged from said ues when saidelevator is moved to a position within said retort.

9. In a retort furnace, a furnace housing, an open bottomed retortdisposed within said housing, a liquid seal for the base of said retort,a lining Within said retort, said retort and lining being spaced bycorrugations forming flues therebetween, means disposed in said retortfor creating a forced circulation of air through said flues, a deflectorplate located adjacent the lower extremity of said flues, and a loadelevator movable to a position adjacent to said deflector plate forsupporting a load for heat treatment within said lining subject to aforced circulation of air through said flues.

10. In a retort furnace, a furnace housing, an open bottomed retortdisposed within said housing, a liquid seal for the base of said retort,said retort having a double wall, corrugations formed in one of saidwalls and forming flues extending between said walls, means disposedadjacent said Walls for creating a forced circulation of air, adeflector plate disposed substantially normal to one of said walls andspaced from the lower extremity of the other of said walls, a loadplatform movable to a position through said deflector plate to saidretort for supporting a load for heat treatment within said retort in aposition Where the load is subjected to the circulatory passage of aircurrents through said flues and through said retort.

11. In a retort furnace, a furnace housing, an open bottomed retortdisposed within said housing, a liquid seal for the base of said retort,a lining within said retort and spaced apart therefrom for forming aflue therebetween, means disposed in said retort for creating a forcedcirculation of air through said flues, a deflector plate locatedadjacent the lower extremity of said flues, and a load elevator movableto a position adjacent to said deflector plate for supporting a load forheat treatment within said lining subject to a forced circulation of airthrough said flues.

12. In a retort furnace, a furnace housing, an open bottomed retortdisposed within said housing, a liquid seal for the base of said retort,a lining within said retort and spaced apart therefrom for. forming aflue therebetween, means disposed in said retort for creating a forcedcirculation of air, a deflector plate disposed substantially normal toone of said walls and spaced from the lower extremity of the other ofsaid walls, a load platform movable to a position through said deflectorplate to said retort for supporting a load for heat treatment withinsaid retort in a position where the load is subjected. to thecirculatory passage of air currents through said flue and through saidretort.

13. In a retort furnace, a furnace housing, an open bottomed retortmounted within said housing, a liquid seal for the base of said retort,a lining within said retort, said retort and said lining being spaced bycorrugations forming flues for the passage of air alternately in contactWith said lining and the wall of said retort about the circumferencethereof, a deflector plate located adjacent the lower extremities ofsaid flues for directing air currents through said flues and into saidretort, and a load elevator movable to a position adjacent saiddeflector plate for supporting a load for heat treatment within saidretort.

14. In a retort furnace, a furnace housing, an open bottomed retortdisposed in said housing, a lining for said retort, said lining andretort being spaced by corrugations for forming flues therebetween forthe circulation of air, a deflector plate carried by the inner wall ofsaid retort and disposed adjacent the lower extremities of said fluesfor directing air discharged by said flues to the interior of saidretort, and a load elevator having a platform adapted to be movedadjacent to said deflector plate for supporting a load within saidretort subject to the circulation of air through the flues adjacent thesides thereof.

15. In a retort furnace, a furnace housing, an open bottomed retortdisposed Within said housing, a liquid seal for the base of said retort,a lining within said retort, said lining and retort being spaced apartby corrugations forming flues therebetween for the longitudinal passageof air in contact with the wall of said retort, a fan member disposedadjacent the upper extremities of said flues for forcing air throughsaid flues, a deflector plate carried by said retort and locatedadjacent. the lower extremities of said flues, and a load elevatorhaving a platform adapted to be'moved adjacent said deflector plate forsupporting a load within said retort subject to the circulation of airthrough said fines and over said deflector plate within said retort.

16. A retort furnace comprising aheating chamber, an open bottom retortpositioned within said chamber, a lining for said retort, flues formedby said retort and said lining, means for causing a forced circulationof air in the said retort and flues, a liquid seal for said retort, andan elevator having a perforated platform supporting a load in heatoperative position within said lining, said elevator being movable withrespect to said retort, said elevator carrying a multiplicity of battleplates thereon, adapted to be cooperative with the said circulation fromthe aforementioned 'flues and said perforations, for directing thecirculation of air currents within said retort.

In testimony whereof I afiix my signature.

FRED A. HANSEN.

